Power and free conveyor system

ABSTRACT

A power and free conveyor system comprising a power track along which carriers are moved by a power conveyor. Each carrier comprises a plurality of substantially identical trolley bodies which are interconnected to one another. The leading trolley body has a combined pusher and holdback assembly thereon which is operatively connected to an actuating member that will simultaneously retract the pusher and holdback portions upon engagement with an obstacle. A succeeding trolley body has a pivoted secondary dog that is normally held out of the path of the conveyor but can be permitted to be moved upwardly into the path of the conveyor for transferring the carrier at transfer points. A trailing trolley body includes a rearwardly extending projection that is adapted to be contacted by the actuating member of a succeeding carrier to stop a succeeding carrier.

Unlted States Patent 1191 1111 3,906,867 Knudsen Sept. 23, 1975 [54] POWER AND FREE CONVEYOR SYSTEM 3,640,226 2/1972 Klamp 104/172 S 4 ,4 l 3 l l 4 6 [75] Inventor: Kenneth F. Knudsen, St. Clair 3 7 4 32 7/ 97 Pnce Gt 3 0 l9 Shores Mlch' Primary ExaminerEvon C. Blunk [73] Assignee: American Chain & Cable Company, Assistant Examiner-Joseph E. Valenza Inc., New York, NY. Attorney, Agent, or F1'rmBarnes, Kisselle, Raisch & 22] Filed: July 5, 1973 Choate [2]] Appl. NO.I 376,623 57 ABSTRACT R lat d Appli a ion D A power and free conveyor system comprising a [63] Continuation of Ser. No. 223,689, Feb. 4, 1972, p w r rack long which carriers are moved by a abandoned. power conveyor. Each carrier comprises a plurality of substantially identical trolley bodies which are inter- [52] US. Cl 104/172 S; 104/89 connected to one another. The leading trolley body [51] Int. C1. B61B 13/00 has a combined pusher and holdback assembly [58] Field of Search 198/177 R, 177 T; thereon which is operatively connected to an actuat- 104/172 B, 172 BT, 172 S, 178, 89, 91, ing member that will simultaneously retract the pusher 93-96, 108; 105/148, 150, 153, 155; and holdback portions upon engagement with an ob 16/97, l02l07 stacle. A succeeding trolley body has a pivoted sec ondary dog that is normally held out of the path of the References C t conveyor but can be permitted. to be moved upwardly UNITED STATES PATENTS into the path of the conveyor for transferring the car- 885 970 4/1908 Barr 16/106 rier at transfer Points A ng trolley body includes 3,1l8:17O 1/1964 Zollinger 16/105 a rearwardly extending Projection that is adapted to 3,193,371 7/19 5 n 05 be contacted by the actuating member of a succeeding 3,196,805 7/1965 Bishop ct a1 104/94 carrier to stop a succeeding carrier. 3,348,496 10/1967 Klamp et al 104/172 S 3,375,790 4/1968 Bishop 104/172 5 10 Clams 18 Drawmg Flgures 3,415,201 12/1968 Czarnecki 104/178 44 65 4S 2/ la 0 EL: I 1 i 1 y I 1 1 I 1 l /o I E l '1: -39 11 1 I O I l/'" f t 0 O 33 US Patent Sept. 23,1975 Sheet 1 Of6 3,906,867

US Patent Sept. 23,1975 Sheet 2 of6 3,906,867

US Patent Sept. 23,1975 Sheet 5 of6 3,906,867

US Patent Sept 23,1975 Sheet 6 of6 3,906,867

POWER AND FREE CONVEYOR SYSTEM This is a continuation of application Ser. No. 223,689, filed Feb. 4, 1972, now abandoned.

This invention relates to power and free conveyor systems.

BACKGROUND OF THE INVENTION In power and free conveyor systems wherein carriers are moved along a trolley or load track by a power conveyor, it is common to provide a construction wherein interengagement between the carrier and the conveyor can be interrupted upon engagement of an object. In addition, such carriers usually utilize holdback dogs which are intended to prevent unconfined forward movement of the carrier. When the power or pusher dog is retracted, the holdback dog usually remainsin position so that the noise is encountered as the pusher of the conveyor successively engages and passes over the pivoted holdback dog.

Another problem with respect to such conveyor systems heretofore made is that the trolleys of the carriers are usually individually made and designed for their function, requiring substantial inventory of parts especially where the carrier comprises a plurality of interconnected trolleys each of which has a different construction. Further, the construction is usually complex making assembling and disassembling difficult especially in the field while the conveyor system is operating. Further, it is heretofore found that substantial rnachining is required for various trolleys.

Among the objects of the invention are to provide a power and free conveyor system wherein the carrier comprises one or more trolleys of substantially identical construction, which trolleys comprise bodies that are made of castings that are identical in construction, that require minimum machining, that are readily assembled and disassembled, that utilize a novel mounting for guide rollers, that provide as for one type of tro l ley for retraction of the holdback dog in a novel manner upon retraction of the pusher dog, that include integral lugs on the pusher dog to provide positive locking with the conveyor chain dog when negotiating a decline.

SUMMARY OF THE INVENTION In accordance with the invention, the power and free conveyor system embodying the invention comprises carriers, each of which comprises a plurality of substantially identical trolley bodies which are interconnected to one another. The leading trolley body has a combined pusher and holdback assembly thereon which is operatively connected to an actuating member that will simultaneously retract the pusher and holdback portions upon engagement with an obstacle. A succeeding trolley body has a pivoted secondary dog that is normally held out of the path of the conveyor but can be permitted to be moved upwardly into the path of the conveyor for transferring the carrier at transfer points. A trailing trolley body includes a rearwardly extending projection that is adapted to be contacted by the actuating member ofa succeeding carrier to stop a succeeding carrier.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary part sectional, part diagrammatic view of a power and free conveyor system embodying the invention;

FIG. 2 is a side elevational view of a trolley body utilized in the trolleys shown in FIG. 1; a

FIG. 3 is an end view of the trolley body shown in FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2;

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 3;

FIG. 6 is a fragmentary view taken in the direction of the arrow 6 in FIG. 5;

FIG. 7 is a fragmentary side elevational view of a modified form of trolley body;

FIG. 8 is a sectional view taken along the line 8-8 in FIG. 7;

FIG. 9 is a part sectional end view of the trolley body shown in FIG. 7 with a wheel thereon;

FIG. 10 is a fragmentary part sectional side elevational view on an enlarged scale of one of the trolleys shown in FIG. 1;

FIG. 11 is a fragmentary view similar to FIG. 10 showing the parts in a different operative position;

FIG. 12 is a part sectional fragmentary plan view of the trolley body shown in FIGS. 10 and 11;

FIG. 13 is a fragmentary sectional view taken along the line 1313 in FIG. 10, parts being broken away;

FIG. 14 is a fragmentary sectional view taken along the line 14-l4 in FIG. 10;

FIG. 15 is a fragmentary part sectional side elevational view of another of the trolleys shown in FIG. 1;

FIG. 16 is a fragmentary plan view of the trolley shown in FIG. 15;

FIG. 17 is a fragmentary side elevational view of a modified form of carrier;

FIG. 18 is a fragmentary sectional view taken along the line 18-18 in FIG. 17.

DESCRIPTION Referring to FIG. 1, the power and free conveyor system shown therein comprises a load or trolley track 10 along which carriers 11 are moved by a conveyor 12 operating on a power track 13 and having longitudinally spaced pushers 14.

The carrier shown in FIG. 1 is typical of that which might be used in a power and free conveyor system such as shown in the copending applications Ser. No. 853,845, filed Aug. 28, 1969, entitled Conveyor System", of Paul Klamp, now US. Pat. No. 3,640,226, issued Feb. 8, 1972, and Ser. No. 30,780, filed Apr. 22, 1970, entitled Conveyor System, of Ivan L. Ross, now US. Pat. No. 3,662,873, issued May. 16, 1972, and comprises longitudinally spaced trolleys l5, 16, 17 that are interconnected by tie bars 18, as presently described.

In accordance with the invention, each of the trolleys l5, 16, 17 utilizes a substantially identical trolley body with the addition of various parts or elements thereon to accommodate the function to be performed by that trolley, as hereinafter described.

Referring to FIGS. 25, the basic trolley body 20 comprises a casting having an axially extending opening 21 therethrough which includes a wide portion 22 that tapers down to a narrower portion 23, the side walls of the portions 22, 23 being straight and parallel.

The body further includes forwardly and rearwardly projecting ears 24 that have openings 25 therein which receive the axles of wheels 26 that engage the flanges of the track 10 to support the trolley on the track 10.

The body further includes forwardly and rearwardly extending projections 27 substantially below the ears 24 that are of generally uniform width in a vertical direction and have horizontal slots 28 which are open ended. The slots 28 are adapted to receive the axles 29 of horizontal guide wheels 30. The wheels 30 comprise roller bearing mounted wheels with an inner race, rollers and an outer race. The shaft 29 has a nut 31 threaded thereon to hold the wheel in position. As shown in FIG. 6, the underside of each projection 27 is provided with a recessed arcuate portion or groove 32 that is adapted to be engaged by a washer 33 to prevent the shaft from moving longitudinally.

In the form of the trolley body shown in FIG. 7, the body comprises a single casting substantially in the same manner as that in FIGS. 26 except that integral laterally extending projections 35 are provided which are subsequently machined off as shown at the broken lines to remove the area 36 and define axles which can then be swaged as shown in FIG. 9 over the inner race of the wheel 26.

As further shown in FIGS. 2-5, the body 20 includes longitudinally spaced openings 34 for mounting plates and other devices as presently described.

With respect to the first mentioned trolley shown in FIG. 1, a trolley body 20 such as described above is utilized. A pusher and holdback assembly 40 is provided in the opening 21 and comprises a vertical pusher member 41 that has the general configuration and dimensions of the opening 21 including spaced upper surfaces 42, 43, spaced lower surfaces 44, 45 connected by tapered surfaces 46, 47. The member 41 is made in the form of a single casting including an upstanding integral pusher dog 48 having a tapered forward surface 49 and a vertical pusher surface 50 which is adapted to be engaged by the pusher 14 of the conveyor.

As shown in FIG. 12, the member 41 includes upstanding walls or projections 51 rearwardly of the surface 50 of dog 48 between which a holdback dog 52 is pivoted by a pin 53 extending through the projections 51. The holdback dog 52 includes a surface 54 that is normally vertical and held in that position by an integral counter-,weighted portion 55 at the rear of the dog 52.

In addition, spaced plates 56 are mounted on the lower end of the trolley body 20 by bolts 57 and nuts 58 extending through holes 34 (FIG. 14). A movable actuating member 59 having an obstacle contacting surface 60 is pivoted between the plates 56 by another bolt 61 and nut 62. The rear end of the actuating member 59 is bifurcated and pivoted to the lower end of the pusher member 41 by a pin 63 extending through spaced portions 64 of the bifurcated end thereof. A rearwardly extending fixed actuating member 59a is provided on the rearmost trolley 17.

By this arrangement, when the movable actuating member 59 encounters an obstacle or the fixed actuating member 59a of a preceding carrier, the actuating member 59 is pivoted clockwise to the broken line position shown in FIG. 10 moving the combined pusher and holdback assembly 40 downwardly thereby not only moving the pusher surface 50 out of the path of the pusher 14 but in addition moving the holdback dog 52 out of the path so that succeeding pushers 14 will not engage and pass over the holdback dog 52 and cause any noise.

As shown in FIG. 12, the forward face of the holdback dog 54 and the forward faces 64 of the projections 51 lie in substantially the same plane providing an extended holdback surface which can be utilized effectively on downward inclines where the pusher 14 is caused to bear against all the surfaces 54, 64 upon reducing the spacing between the conveyor track and the load track 10.

By providing a flat surface 42 on the trolley body and a complementary surface 65 on pusher member 41, a substantial contact is provided between the pusher member 41 and the body that minimizes any tendency for the member 41 to move downwardly when a pusher 14 on the conveyor chain first engages the pusher 48 on the carrier. The surface-to-surface contact between these two surfaces 42, 65 produces friction that thereby obviates inadvertent movement of the member 41 downwardly that might cause disengagement of the trolley from pusher 14.

With respect to the intermediate trolley 16 shown in FIG. 15 wherein a secondary dog is needed for transfers such as fully defined in the aforementioned patent applications, an identical trolley body 20 is utilized ex cept that the secondary dog is pivoted by pin 71 so that its upper end 72 is urged upwardly into the path of the pusher 14 by a counter-weighted lower end 73 that extends downwardly into the opening 21. The upper end 72 has a surface 74 defining a secondary pusher surface. The dog 70 further includes laterally extending ears or projections 75 that are adapted to engage the flanges of the track 10 to normally hold the dog 70 out of the path of the pusher 14. Where a transfer is to be achieved, portions of the track are cut away to permit the dog 70 to be pivoted upwardly under the action of the counter-weight 73 into the path of the pusher 14 as fully set forth in the aforementioned applications.

The interconnection between the trolleys 15, 16 is achieved by hooks 76 that are mounted on the plates 56 in the case of the trolley 15 and 77 in the case of the trolley 16. The tie bar 18 includes U-bolts 19 that engage the openings in the member 76.

In the form of the invention shown in FIGS. 17 and 18, the carrier comprises a single trolley combining the structures of the forward and trailing trolleys 15, 17 in FIG. 1. The rearwardly extending fixed actuating member 59a on the trailing trolley in FIG. 1 is mounted on the leading trolley by utilizing longer bolts.

I claim:

1. In a power and free conveyor system, the combination comprising means defining a carrier track,

a carrier movable along said track,

said carrier comprising a plurality of trolleys,

power means extending along the path of the track,

said power means having carrier engaging means thereon,

each said trolley comprising a one-piece trolley body,

each said trolley body having longitudinally spaced wheels thereon engaging said track, said trolley bodies being substantially identical,

the leading trolley of the carrier having a pusher dog therein movable toward and away from the engaging means of the power track, I

a pair of transversely spaced plates mounted on said body, I actuating means mounted on said plates and connected to said pusher dog for moving said pusher dog out of the path of the carrier engaging means on the power means in response to engagement of said actuating means with an obstacle or a preced ing carrier,

and means extending between the plates of adjacent trolleys pivotally interconnecting said trolleys, said pusher dog comprising a part of a combined pusher dog and holdback dog assembly,

said combined pusher and holdback dog assembly comprising a pusher member having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said member and having a surface yieldingly urged upwardly in forwardly facing relation,

such that said pusher member and said holdback dog are moved out of the path of the carrier engaging means by engagement of the actuating means with an obstacle or a preceding carrier.

2. The combination set forth in claim 1 wherein said pusher member and said trolley body have interengaging flat surfaces which are engaged when the carrier engaging means of the power means engages the pusher dog of said combined pusher and holdback dog assembly.

3. The combination set forth in claim 1 wherein said forwardly facing surface of said holdback dog is fiat and said pusher member includes a substantially flat portion thereon lying in substantially the same plane as the flat surface of said holdback dog when said holdback dog is in normal position such that the flat portion of the pusher member extends the flat surface of the holdback dog.

4. The combination set forth in claim 1 wherein each said trolley body comprises longitudinally spaced transverse axle receiving openings,

a vertical opening extending entirely therethrough,

said pusher and holdback assembly being movable in said last-mentioned vertical opening of the leading trolley.

5. The combination set forth in claim 1 wherein said trolley body includes forwardly and rearwardly directed cantilever portions having open-ended vertical slots therein and guide wheel assemblies having axles disposed in said slots,

each said forwardly and rearwardly directed portion including a recessed groove therein adjacent said slot which is generally arcuate,

said guide wheel assembly having a complementary portion thereof engaging said recessed groove and preventing longitudinal movement with respect to the trolley body when in such engagement,

such that the guide wheel assemblies may be removed from the trolley body at substantially any point along the carrier track without removing said trolley from said carrier track.

6. The combination set forth in claim 4 including a second pusher movably mounted in the vertical opening of the trolley body of a succeeding trolley and haw ing a portion thereof extending upwardly into the path of the engaging means of the power means and another portion which is counterweighted and extends downwardly into the vertical opening of the trolley body.

7. For use in a power and free conveyor system, the combination comprising a carrier adapted to be moved along a track,

said carrier comprising a plurality of interconnected trolleys,

said trolleys having. substantially identical trolley bodies,

each said trolley body having wheels thereon adapted to engage a track,

a pair of transversely spaced plates mounted on said body,

each said trolley body comprising a one-piece casting having longitudinally spaced transverse axle receiving openings, i

a vertical opening extending entirely therethrough,

substantially identical axles in said transverse openings,

and substantially identical wheels on said axles such that said bodies, axles and wheels are interchangeable, and means extending between the plates of adjacent trolleys pivotally interconnecting said trolleys,

one of said-trolleys having a combined pusher and holdback dog assembly in the vertical opening thereof comprising a pusher member having a rearwardly facing surface defining the pusher dog and a holdback dog pivoted to said member and having a surface normally in forwardly facing relation,

actuating means mounted on said plates and connected to said pusher dog for moving said combined pusher dog and holdback dog assembly out of the path of carrier engaging means on power means along a track in response to engagement of said actuating means with an obstacle or a preceding carrier.

8. The combination set forth in claim 7 wherein said pusher member and said trolley body have interengaging flat surfaces which are engaged when the carrier engaging means of the power means engages the pusher dog of said combined pusher and holdback dog assembly.

9. For use in a power and free conveyor, a trolley comprising a trolley body having a vertical opening therethrough, i

said trolley body having wheels thereon adapted to engage a track,

a combined pusher dog and holdback dog assembly movable in said vertical opening,

said combined pusher and holdback dog assembly comprising a pusher member having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said member and having a surface yieldingly urged upwardly in forwardly facing relation,

such that said pusher member and said holdback dog are moved out of the path of a carrier engaging means by engagement of the actuating means with an obstacle or a preceding carrier,

said trolley body including forwardly and rearwardly directed cantilever portions having open-ended vertical slots therein and guide wheel assemblies having axles disposed in said slots,

each said forwardly and rearwardly directed portion including a recessed portion therein adjacent said slot which is generally arcuate,

said guide wheel assembly having a portion thereof engaging said recessed portion and preventing longitudinal movement with respect to the trolley body when in such engagement,

comprising a pusher member movable vertically on said body and having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said pusher member and having a surface yieldingly urged upwardly in forwardly facing relation,

actuating means connected to said pusher member for moving said pusher member and said holdback dog vertically out of the path of a carrier engaging means in response to engagement of the actuating means with an obstacle or a preceding carrier. 

1. In a power and free conveyor system, the combination comprising means defining a carrier track, a carrier movable along said track, said carrier comprising a plurality of trolleys, power means extending along the path of the track, said power means having carrier engaging means thereon, each said trolley comprising a one-piece trolley body, each said trolley body having longitudinally spaced wheels thereon engaging said track, said trolley bodies being substantially identical, the leading trolley of the carrier having a pusher dog therein movable toward and away from the engaging means of the power track, a pair of transversely spaced plates mounted on said body, actuating means mounted on said plates and connected to said pusher dog for moving said pusher dog out of the path of the carrier engaging means on the power means in response to engagement of said actuating means with an obstacle or a preceding carrier, and means extending between the plates of adjacent trolleys pivotally interconnecting said trolleys, said pusher dog comprising a part of a combined pusher dog and holdback dog assembly, said combined pusher and holdback dog assembly comprising a pusher member having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said member and having a surface yieldingly urged upwardly in forwardly facing relation, such that said pusher member and said holdback dog are moved out of the path of the carrier engaging means by engagement of the actuating means with an obstacle or a preceding carrier.
 2. The combination set forth in claim 1 wherein said pusher member and said trolley body have interengaging flat surfaces which are engaged when the carrier engaging means of the power means engages the pusher dog of said combined pusher and holdback dog assembly.
 3. The combination set forth in claim 1 wherein said forwardly facing surface of said holdback dog is flat and said pusher member includes a substantially flat portion thereon lying in substantially the same plane as the flat surface of said holdback dog when said hOldback dog is in normal position such that the flat portion of the pusher member extends the flat surface of the holdback dog.
 4. The combination set forth in claim 1 wherein each said trolley body comprises longitudinally spaced transverse axle receiving openings, a vertical opening extending entirely therethrough, said pusher and holdback assembly being movable in said last-mentioned vertical opening of the leading trolley.
 5. The combination set forth in claim 1 wherein said trolley body includes forwardly and rearwardly directed cantilever portions having open-ended vertical slots therein and guide wheel assemblies having axles disposed in said slots, each said forwardly and rearwardly directed portion including a recessed groove therein adjacent said slot which is generally arcuate, said guide wheel assembly having a complementary portion thereof engaging said recessed groove and preventing longitudinal movement with respect to the trolley body when in such engagement, such that the guide wheel assemblies may be removed from the trolley body at substantially any point along the carrier track without removing said trolley from said carrier track.
 6. The combination set forth in claim 4 including a second pusher movably mounted in the vertical opening of the trolley body of a succeeding trolley and having a portion thereof extending upwardly into the path of the engaging means of the power means and another portion which is counterweighted and extends downwardly into the vertical opening of the trolley body.
 7. For use in a power and free conveyor system, the combination comprising a carrier adapted to be moved along a track, said carrier comprising a plurality of interconnected trolleys, said trolleys having substantially identical trolley bodies, each said trolley body having wheels thereon adapted to engage a track, a pair of transversely spaced plates mounted on said body, each said trolley body comprising a one-piece casting having longitudinally spaced transverse axle receiving openings, a vertical opening extending entirely therethrough, substantially identical axles in said transverse openings, and substantially identical wheels on said axles such that said bodies, axles and wheels are interchangeable, and means extending between the plates of adjacent trolleys pivotally interconnecting said trolleys, one of said trolleys having a combined pusher and holdback dog assembly in the vertical opening thereof comprising a pusher member having a rearwardly facing surface defining the pusher dog and a holdback dog pivoted to said member and having a surface normally in forwardly facing relation, actuating means mounted on said plates and connected to said pusher dog for moving said combined pusher dog and holdback dog assembly out of the path of carrier engaging means on power means along a track in response to engagement of said actuating means with an obstacle or a preceding carrier.
 8. The combination set forth in claim 7 wherein said pusher member and said trolley body have interengaging flat surfaces which are engaged when the carrier engaging means of the power means engages the pusher dog of said combined pusher and holdback dog assembly.
 9. For use in a power and free conveyor, a trolley comprising a trolley body having a vertical opening therethrough, said trolley body having wheels thereon adapted to engage a track, a combined pusher dog and holdback dog assembly movable in said vertical opening, said combined pusher and holdback dog assembly comprising a pusher member having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said member and having a surface yieldingly urged upwardly in forwardly facing relation, such that said pusher member and said holdback dog are moved out of the path of a carrier engaging means by engagement of the actuating means with an obstacle or a preceding carrier, SAID trolley body including forwardly and rearwardly directed cantilever portions having open-ended vertical slots therein and guide wheel assemblies having axles disposed in said slots, each said forwardly and rearwardly directed portion including a recessed portion therein adjacent said slot which is generally arcuate, said guide wheel assembly having a portion thereof engaging said recessed portion and preventing longitudinal movement with respect to the trolley body when in such engagement, such that the guide wheel assemblies may be removed from the trolley body at substantially any point along a carrier track.
 10. For use in a power and free conveyor, a trolley comprising a trolley body, said trolley body having wheels thereon adapted to engage a track, a combined pusher dog and holdback dog assembly, means for supporting said combined pusher and holdback assembly on said trolley body for vertical movement, said combined pusher and holdback dog assembly comprising a pusher member movable vertically on said body and having a rearwardly facing surface defining said pusher dog and a holdback dog pivoted to said pusher member and having a surface yieldingly urged upwardly in forwardly facing relation, actuating means connected to said pusher member for moving said pusher member and said holdback dog vertically out of the path of a carrier engaging means in response to engagement of the actuating means with an obstacle or a preceding carrier. 